Bathroom lights and extractor fan

[ban-all-sheds]

Can anyone help please?

//www.diynot.com/wiki/electrics:lighting

//www.diynot.com/wiki/electrics:fan

 

[matty25]

Okay ban-all-sheds, I have read and re-read and re-read the notes and links which you posted, i think i could wire the three downlights to the switch as follows:-

Let me know what you think / if this is correct.

Just need to sort out wiring the extract fan to the other gang then.

Damn just realised i should also take the earth and neutral wires through to the next fitting too.

Regards
Matt

 

[rebuke]

What I would do is instead of just running T&E to the switch, I'd run three core and earth, then of your three cores, one is the permanent live, one is the switched live for the light, and one is the switched live for the fan. Your junction box would be 'interesting' due to the amount of connections (it may be easier to put in a larger adaptable box or similar), but essentially you then wire it as you have done, except take a feed to the fan from the neutral, earth, and new switched live from the switch.

In the switch you'd also need a small bit of wire linking the two switches together so they both had the permanent live...

 

[matty25]

What I would do is instead of just running T&E to the switch, I'd run three core and earth, then of your three cores, one is the permanent live, one is the switched live for the light, and one is the switched live for the fan. Your junction box would be 'interesting' due to the amount of connections (it may be easier to put in a larger adaptable box or similar), but essentially you then wire it as you have done, except take a feed to the fan from the neutral, earth, and new switched live from the switch.

In the switch you'd also need a small bit of wire linking the two switches together so they both had the permanent live...

Thanks Rebuke, I was thinking of wiring the fan in like this:

Is this correct? will it work?

Regards
Matt

 

[rebuke]

The neutral from your fan won't be unused, it has to connect back to the supply neutral, otherwise the fan won't work...

I would do it as follows (don't have time to try and draw a diagram, sorry):

Wire the three downlighters into one junction box, with a single cable coming out (just to simplify the rest of the system and not have a stupid number of wires in one box!).
Put in an adapatable box, which has coming in cables from:
T&E Supply (and possibly onward supply if present) (a)
T&E to downlight junction box (b)
Three core & earth to light switch (c)
Three core & earth to fan isolator (d)

I'd then wire the supply (a) live to one core of (c) (brown if using new colours), and one core of (d). In the switch, this would have a link between the two switch terminals. I'd then apply some brown sleeving, and wire the other two cores of (c) (black and grey if using new colours) to the two switches. In the adaptable box, I'd wire one of these into the live from (b), and the other into the switched live to the fan (d). I'd finally connect all the earths and neutrals together (be careful to identify which is a neutral and which is a switched live - all your switched lives should have brown sleeving on)...

 

[matty25]

Thank you rebuke, will let you know how i get on.

Regards
Matt

 

[ban-all-sheds]

Is it so difficult to just say this wire goes here and that wire goes there, connect this to that etc..

"Give a man a fish...."

No - it isn't difficult, but nobody should ever do "electrics-by-numbers", just putting wires into terminals without understanding why, and how it all works.

I have re-read the documents and links you posted. But as you can see my application/situation is slightly different to the examples documented.

But similar enough for you to be able to work out how to do what you want...

Okay ban-all-sheds, I have read and re-read and re-read the notes and links which you posted, i think i could wire the three downlights to the switch as follows:-

http://e.imagehost.org/0559/Untitled_2.jpg

Let me know what you think / if this is correct.

Yup - apart from the circuit earth & neutral which you spotted.

Thanks Rebuke, I was thinking of wiring the fan in like this:

http://e.imagehost.org/0473/Untitled_2_8.jpg

Is this correct? will it work?

Why do you think circuits have neutral conductors?

 

[matty25]

Thanks for your help ban-all-sheds, to be honest figuring it out for myself I actually feel that i have learnt something now.

I think this is what i need to do as explained by rebuke:

Is this correct? I believe so.

Regards
Matt

 

[rebuke]

Looks good to me, only things I can see missing are the brown sleeving on the switched live to the fan (as you've already spotted), also some blue sleeving on both ends of the yellow neutral in the 3-core to the fan (or should it be black sleeving as that's an old colours cable - I'm not sure...). There should also be an earth connection between the switch (or at least the back box if no terminal on the switch) and the other earths. If it's a plastic fronted switch and back box with no earth terminals, then just put it in a bit of choc block at the switch end.

 

[matty25]

Looks good to me, only things I can see missing are the brown sleeving on the switched live to the fan (as you've already spotted), also some blue sleeving on both ends of the yellow neutral in the 3-core to the fan (or should it be black sleeving as that's an old colours cable - I'm not sure...). There should also be an earth connection between the switch (or at least the back box if no terminal on the switch) and the other earths. If it's a plastic fronted switch and back box with no earth terminals, then just put it in a bit of choc block at the switch end.

Thanks Rebuke, i've updated diagram, should be okay now?

A big thank you for all of your help, it is very much appreciated.

Regards
Matt

 

[rebuke]

You appear to have ended up on your diagram with a very strange set of colours on the cable to the fan - it's presumably either old colours (red/yellow/blue), or new colours (brown/black/grey), but you seem to have brown/yellow/grey?

 

[matty25]

You appear to have ended up on your diagram with a very strange set of colours on the cable to the fan - it's presumably either old colours (red/yellow/blue), or new colours (brown/black/grey), but you seem to have brown/yellow/grey?

Hi rebuke, the colours arent clear in the pic but the colours from the fan are:

Red (perm live - now brown)
Blue (switched live - now grey)
Solid yellow (neutral - now black)
Yellow & Green (earth)

Think this is right.

Regards
Matt

 

[ban-all-sheds]

4-way JBs give you the terminals you need for the L/N/E of the circuit loop cable, and for the switched live return from the switch.

As you've got one anyway for the lights, I wouldn't bother with an adaptable box as well.

Either:

Only have the adaptable box with a 5-way strip of choc-block in it. You can easily use a single 3C+E switch drop cable if you want.

Or:

Just add a 2nd 4-way JB, take the circuit cable into the 1st, then the 2nd, and then onwards. Use one JB for the lights and one for the fan. If you position them right next to each other so that conductors can run between them without becoming exposed you can still use a single 3C+E drop cable to the switches if you want.

 

[matt1e]

matt
using yellow as neutral and blue as switched live is confusing to say the least! no doubt you are going to wire this anyway so at least reverse these two confections ie
blue = neutral
yellow = switched live

this will at least make it less confusing to the next man that gets to open up your JB

matt

 

[ban-all-sheds]

Everything should be sleeved at each end to indicate its function, according to whatever colour code is being used.

I hadn't spotted this, as it came in while I was doing my previous reply:

Red (perm live - now brown)
Blue (switched live - now grey)
Solid yellow (neutral - now black)
Yellow & Green (earth)

Black is no longer the colour for neutral, it's one of the phase colours (was yellow/L2), so using it will not indicate that that conductor is neutral - you must not mix'n'match - either stick to Red/Yellow/Blue/Black or Brown/Black/Grey/Blue, but not a made-up hybrid.